Scan conversion device and electronic camera

ABSTRACT

A scan conversion device includes a first buffer unit, a pixel packing unit, a second buffer unit, and a scan output unit. The first buffer unit stores therein pixel signals of the input image on every line in a main scanning direction thereof. The pixel packing unit groups N (N≧2) pixel signals on each line into pixel signal packs according to a predetermined pixel combination rule, and outputs them sequentially. The second buffer unit stores therein the pixel signal packs and aligns them in a second main scanning direction different from the main scanning direction. The scan output unit sequentially outputs the pixel signal packs aligned in the second main scanning direction. According to this configuration, a scan pattern of the input image is changed into a scan pattern of outputting every N output lines in the second main scanning direction.

CROSS REFERENCE TO RELATED APPLICATION

This is a Division of application Ser. No. 11/290,582 filed Dec. 1,2005, which in turn is based upon and claims the benefit of priorityfrom Japanese Patent Application No. 2004-366037, filed on Dec. 17,2004. The disclosure of the prior application is hereby incorporated byreference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a scan conversion device for convertinga scan pattern of an input image. The present invention also relates toan electronic camera that includes the scan conversion device.

2. Description of the Related Art

Recent increase of the number of pixels of an imaging device has causedmuch increase of time required for reading out data from the pixelsthereof. Providing a plurality of number of output channels for theimaging device to heighten a rate of pixel readout is a way to solvethis problem.

For example, there is a known technique in which pixel signals from theimaging device are divided in a unit of regions of a screen, scanninglines or color components for parallel and simultaneous readout using aplurality of output channels.

However, there is a problem in using a plurality of output channels thatit is required to provide a plurality of paths for transferring thepixel signals in the imaging device, which limits the design of theimaging device in terms of device layout, signal interference, and thelike. Thus, an order of main scan or sub-scan of the pixel signals maybe reversed for each channel (from/to descending to/from ascendingorder), for example. For another example, a main scanning direction maybe changed from a generally used horizontal direction of a screen to avertical direction.

As described above, the restriction to the scan pattern causes varioustroubles in later signal processing. For example, when adjacent pixelsignals on the screen are output at different timings, it is notpossible to align, in a pipeline way, pixel signals of the minimumprocessing unit for signal processing. In addition, if a pixel signalrequired first in signal processing is output later, the signalprocessing will be delayed.

Note that there is a known exemplary technique disclosed in JapaneseUnexamined Patent Application Publication No. 2004-260265 for outputtinga serial output of an imaging device in the form of parallel outputs ona pixel block basis.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a noveltechnique for converting a scan pattern of an input image.

It is another object of the present invention to add processing of apixel signal pack (described later) to the scan pattern conversionprocessing, thereby improving efficiency and speed of the conversionprocessing.

It is still another object of the present invention to scan and outputpixel signals using a converted scan pattern through a plurality ofoutput channels, achieving an increase in a processing rate in latersignal processing.

The present invention is now described.

[1] A scan conversion device of the present invention for converting ascan pattern of an input image includes a first buffer unit, a pixelpacking unit, a second buffer unit, and a scan output unit. The firstbuffer unit temporarily stores therein pixel signals of the input imageon each read-out line in a main scanning direction of the input image.

The pixel packing unit selects every N (N≧2) pixel signals from pixelsignals on the read-out line in accordance with a predetermined pixelcombination rule. The pixel packing unit groups the selected signalsinto pixel signal packs for output.

The second buffer unit temporarily stores therein the pixel signal packsand aligns them in a second main scanning direction that is differentfrom the main scanning direction.

The scan output unit sequentially scans, for output, the pixel signalpacks aligned in the second main scanning direction in the second bufferunit.

According to this configuration, it is possible to change a scan patternof the input image into a scan pattern in which every N output lines inthe second main scanning direction are output.

[2] It is preferable that the pixel packing unit sequentially selectpixel signals of pixels located at symmetric positions with respect to amidpoint of the read-out line and group them into the pixel signal packsfor output. The scan output unit starts scan output at pixel signalslocated at both ends of the read-out line, grouped as pixel signal packsand aligned in the second main scanning direction, and continues thescan output of the pixel signal packs sequentially in inward directionsof the read-out line.

According to this configuration, it is possible to change the scanpattern of the input image into a scan pattern in which scanning of theoutput lines starts from both ends of a screen and then continues tomove toward a middle of the screen symmetrically (i.e., closing-in scanwhich moves similarly to a closing double swing door).

[3] It is preferable that the pixel packing unit sequentially selectpixel signals located at symmetric positions with respect to a midpointof the read-out line and group them into the pixel signal packs foroutput. The scan output unit starts scan output at pixel signals nearthe midpoint of the read-out line, grouped as the pixel signal packs andaligned in the second main scanning direction, and then continues thescan output of the pixel signal packs sequentially in outward directionsof the read-out line.

According to this configuration, it is possible to change the scanpattern of the input image into a scan pattern in which scanning of theoutput lines starts from pixel signals near the middle of the screen andthen continues to move toward both ends of the screen symmetrically(i.e., split-open scan which moves similarly to an opening double swingdoor).

[4] It is preferable that the pixel packing unit select N pixel signalsfrom pixels on the read-out line at a predetermined interval and groupthem into pixel signal packs for output. The scan output unit sub-scans,in one direction of the read-out line, scan outputs of the pixel signalpacks aligned in the second main scanning direction.

According to this configuration, it is possible to change the scanpattern of the input image into a scan pattern in which N dividedregions in the screen are scanned for output in parallel (i.e., N-bladescan which moves similarly to a N-blade razor skimming the screen).

[5] It is also preferable that the pixel signals be color signals eachcontaining color information.

[6] An electronic camera of the present invention includes theabove-mentioned scan conversion device and an imaging unitphotoelectrically converting an image of a subject and reading out pixelsignals. In this electronic camera, the scan conversion device convertsa scan pattern of the pixel signals read out from the imaging unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The nature, principle, and utility of the invention will become moreapparent from the following detailed description when read inconjunction with the accompanying drawings in which like parts aredesignated by identical reference numbers, in which:

FIG. 1 shows the configuration of an electronic camera 11;

FIG. 2 shows a process for generating pixel signal packs;

FIGS. 3A and 3B show a process for converting a scan pattern into apattern of closing-in scan;

FIGS. 4A and 4B show a process for converting a scan pattern into apattern of split-open scan;

FIGS. 5A and 5B show a process for converting a scan pattern into apattern of N-blade scan;

FIG. 6 shows a pixel arrangement in an imaging device 13;

FIG. 7 shows four scan outputs chA to chD of the imaging device 13;

FIG. 8 shows a process for generating pixel signal packs for an Rcomponent;

FIG. 9 shows a process for generating a pixel signal packs for a Grcomponent;

FIG. 10 shows a process for converting a scan pattern; and

FIGS. 11A and 11B show an exemplary converted scan pattern.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention are now described indetail with reference to the drawings.

Embodiment 1

FIG. 1 shows the configuration of an electronic camera 11.

Referring to FIG. 1, a lens 12 is mounted on the electronic camera 11. Alight-receiving surface of an imaging device 13 is arranged in an imagespace of the lens 12. Pixel signals output from the imaging device 13are converted into digital signals by an A/D converter 14 and are theninput to a pixel processing unit 15 sequentially. The pixel processingunit 15 performs one or more processings feasible for each one of thepixel signals independently (e.g., correction for a defective pixel) ina pipeline manner. The thus processed pixel signals are input to a scanconversion device 16.

The scan conversion device 16 includes a scan control unit 17, a linebuffer 18, and a memory 19. The line buffer 18 temporarily stores pixelsignals corresponding to a read-out line in a main scanning direction ofthe imaging device 13. The memory 19 is a buffer which can be read fromand written to at least on a pixel signal pack basis (described later).The scan control unit 17 converts a scan pattern of pixel signals inputthereto by using the above configuration.

An output of the scan conversion device 16 is input to a scan imageprocessing unit 20. The scan image processing unit 20 sequentiallyperforms one or more processings in pixel scanning order (e.g.,arithmetic processing referring to an adjacent pixel, or OB clamp).

The pixel signals for which the above processes are finished aretemporarily stored in an image buffer 21. An image processing unit 22performs two-dimensional image processing (e.g., color interpolation oredge enhancement) for the pixel signals in the image buffer 21. An imagecompression unit 23 performs image compression for the pixel signalsafter the image processing, and then records these pixel signals in amemory card 24.

[Process for Generating Pixel Signal Packs]

Next, a process for generating pixel signal packs is described. Thisprocess is a feature of the first embodiment.

FIG. 2 shows the process for generating pixel signal packs (a signalflow) in the first embodiment.

Photoelectric conversion is performed for an image of a subject on apixel to pixel basis on the light-receiving surface of the imagingdevice 13, so that pixel signals of n pixels in a vertical direction x mpixels in a horizontal direction are generated. The pixel signals aresequentially read out from the imaging device 13 with the verticaldirection regarded as a main scanning direction.

The thus read pixel signals are sequentially input to the scanconversion device 16 through the A/D converter 14 and the imageprocessing unit 15. The scan control unit 17 of the scan conversiondevice 16 inputs these pixel signals to the line buffer 18 on a read-outline basis. One read-out line is formed of one vertical line of pixels(n pixels). The line buffer 18 temporarily stores the thus input pixelsignals.

The scan control unit 17 reads out N (N=2 in this example) pixel signalsfrom the line buffer 18 and generates a pixel signal pack. The pixelsignal pack is a group of N pixel signals as a unit that can betransferred in block. The generation of the pixel signal pack can beachieved by a bit packing process, for example.

Outputs P1 to P3 in FIG. 2 represent examples of the generation of pixelsignal packs.

In the output P1, pixel signals of pixels located at symmetric positionswith respect to a midpoint of the read-out line (i.e., a midpointbetween the c-th pixel and (c+1)th pixel where c=n/2) are sequentiallygrouped. In this manner, pixel signal packs are sequentially generated.First, a pixel signal pack of pixel signals of pixels (1, 1) and (1, n)located at both ends of the read-out line is output. Then, pixel signalpacks of pixel signals of inner pixels are sequentially output. Finally,a pixel signal pack of pixel signals of pixels located at the center ofthe read-out line, i.e., pixels (1, c) and (1, c+1) is output.

In the output P2, pixel signals of pixels located at symmetric positionswith respect to the midpoint of the read-out line are grouped in asimilar manner to that of the output P1, thereby generating pixel signalpacks. However, the order of outputting the pixel signal packs in theoutput P2 is reversed from that in the output P1. First, the pixelsignal pack of the pixel signals of pixels (1, c) and (1, c+1) that arelocated at the center of the read-out line is output. Then, the pixelsignal packs of pixel signals of outer pixels are sequentially outputuntil the pixel signal pack of the pixel signals of pixels (1, 1) and(1, n) that are located at both ends of the read-out line is output.

On the other hand, in the output P3, pixel signals are selected andgrouped at a predetermined interval (c in this example) from theread-out line so as to generate a pixel signal pack. The pixel signalpacks generated in this manner are sequentially output.

It is preferable that the scan conversion device 16 include a pluralityof (e.g., two) line buffers 18 for which reading and writing can beindependently performed. In this case, during a period in which one ofthe line buffers 18 outputs the pixel signal packs, pixel signals of thenext line can be stored in the other line buffer 18. By sequentiallyexchanging roles of the line buffers 18 in this manner, it is possibleto read and write pixel signals without delay.

[Conversion Process of a Scan Pattern]

The scan control unit 17 scans and writes the pixel signal packsgenerated through the line buffer 18 into the memory 19, and stores onlyas many the pixel signal packs as necessary to perform conversion of ascan pattern in the memory 19.

Then, the scan control unit 17 scans and reads out the pixel signalpacks from the memory 19 in a different scan pattern from the pattern ofthe write scan. The scan pattern is converted according to a differencebetween scanning paths for write scan and for read scan.

It is preferable that the scan conversion device 16 include a pluralityof (e.g., two) memories 19 for which reading and writing can beperformed independently. In this case, during a period in which the readscan is performed for one of the memories 19, the write scan for pixelsignal packs of the next screen can be performed for the other memory19. By sequentially exchanging roles of the memories 19 in this manner,it is possible to perform the read and write scans for the pixel signalpacks without delay.

It is preferable that the memory 19 be a memory for which reading andwriting can be performed by burst transfer. In this case, time requiredfor converting a scan pattern can be shortened by using burst transferin the read and/or write scan.

Next, exemplary manners of conversion of a scan pattern are describedbased on specific examples.

[1] Closing-In Type Scan

FIGS. 3A and 3B show a process for converting a scan pattern into apattern of closing-in scan.

The scan control unit 17 scans and writes pixel signal packs for onescreen, that are obtained by grouping pixel signals of pixels located atsymmetrical positions (e.g., pixel signal packs in the output P1 or P2in FIG. 2), into the memory 19.

In this manner, (n/2) scan lines each containing m pixel signal packsaligned in the horizontal direction are obtained in the memory 19. Thescan control unit 17 scans the memory 19 for reading, as shown in FIG.3A. That is, the scan control unit 17 reads out the (n/2) scan lines inan order from pixel signal packs of pixel signals of pixels located atupper and lower ends of the screen to pixel signal packs correspondingto pixels located at the center.

As a result of the read scan, a scan pattern is achieved in which scanof output lines starts from upper and lower ends of the screen andsymmetrically progresses toward the middle of the screen (i.e., apattern of closing-in scan which moves similarly to a closing doubleswing door), as shown in FIG. 3B.

[2] Split-Open Scan

Next, a process for converting a scan pattern into a pattern ofsplit-open scan is described as another exemplary conversion of the scanpattern.

FIGS. 4A and 4B show this conversion process.

The scan control unit 17 scans and writes pixel signal packs for onescreen, that are obtained by grouping pixel signals of pixels located atsymmetrical positions (e.g., pixel signal packs in the output P1 or P2in FIG. 2), into the memory 19.

In this manner, (n/2) scan lines each containing m pixel signal packsaligned in the horizontal direction are obtained in the memory 19. Thescan control unit 17 performs scan for reading for the memory 19, asshown in FIG. 4A. That is, the scan control unit 17 reads out the (n/2)scan lines in an order from pixel signal packs of pixel signals ofpixels located at the middle of the screen to pixel signal packs ofpixel signals of pixels located at upper and lower ends.

As a result of the read scanning, a scan pattern is achieved in whichscanning of output lines starts from the middle of the screen andsymmetrically continues to move upwards and downwards (i.e., a patternof split-open scan which moves similarly to an opening double swingdoor), as shown in FIG. 5B.

[3] N-Blade Scan

Next, a process for converting a scan pattern into a pattern of N-bladescan is described as another exemplary conversion of the scan pattern.

FIGS. 5A and 5B show this process.

The scan control unit 17 scans and writes pixel signal packs for onescreen, that are obtained by grouping pixel signals at a predeterminedinterval (i.e., pixel signal packs in the output P3 in FIG. 2), into thememory 19.

In this manner, (n/2) scan lines each containing m pixel signal packsaligned in the horizontal direction are obtained in the memory 19. Thescan control unit 17 performs scan for reading for the memory 19, asshown in FIG. 5A. That is, the (n/2) scan lines are read out in an orderfrom pixel signal packs of pixel signals of upper pixels in the screento pixel signal packs of pixel signals of lower pixels.

As a result of the read scanning, a scan pattern is achieved in whichscanning is performed for each of divided regions of the screen (i.e., apattern of N-blade scan which moves similarly to a N-blade razorskimming the screen), as shown in FIG. 5B.

Effects of the First Embodiment and Others

As described above, pixel signal packs are generated by grouping N (N=2in this example) of n pixel signals of pixels in a vertical line in thefirst embodiment. After the packing process, the number of signals to beprocessed (i.e., the number of the pixel signal packs) is reduced to 1/Ntimes. This reduction increases time margin of the process forconverting a scan pattern. Therefore, the scan conversion device 16 canbe achieved that can accept an imaging device 13 having high resolution(a large number of pixels).

Moreover, in the first embodiment, each of the pixel signal packs isgenerated by grouping N pixel signals in the main scanning direction ofthe imaging device 13. The thus generated pixel signal packs are groupedin the second main scanning direction and are scanned and output. Thisprocess can provide a scan pattern that enables the use of N outputlines. Since the use of a plurality of output lines is enabled, it isalso possible to perform signal processing later by using a plurality oflines. Thus, it is easy to increase a rate of signal processing in theelectronic camera 11.

In the closing-in scan, the output lines at both ends (upper and lowerends in this example) of the screen are output first. Generally, thereare reference regions 50 a and 50 b typified by optical black regions atboth ends of a screen, as shown in FIG. 3B. With conventional scanpattern, it is impossible to obtain signals of the reference regions 50a and 50 b located at both ends in the sub-scanning direction of thescreen together in advance of pixel signals of an effective pixelregion. However, when closing—in scan is performed as described above,it is possible to obtain the signals of the reference regions 50 a and50 b together in advance of the signals of the effective pixel signal.Thus, before the effective pixel region is scanned and output, selectionwhether the reference regions 50 a and 50 b are used or not, signalprocessing of the reference regions 50 a and 50 b, and the like can beperformed.

Embodiment 2

Next, the imaging device 13 in the electronic camera 11 scans the pixelsignals and outputs them on a plurality of channels.

FIG. 6 shows a pixel arrangement in an imaging device 13. The imagingdevice 13 generates pixel signals of n pixels in the verticaldirection×m pixels in the horizontal direction. The pixel signal is acolor signal containing information on one of colors, Gr, Gb, R, and B.These colors are arranged in a bayer pattern.

FIG. 7 shows four scan outputs chA, chB, chC, and chD of the imagingdevice 13.

As shown in FIG. 7, the imaging device 13 divides pixel signals of thepixels arranged as shown in FIG. 6 into a first field formed of R linesand Gr lines and a second field formed of Gb lines and B lines and readsthe pixel signals out by sequentially reading the first field and thesecond field, i.e., performing reading twice.

R components of the first field are divided into two groups that arerespectively read out on two scan outputs chA and chB in parallel at thesame time. Gr components of the first field are divided into two groupsthat are respectively read out on two scan outputs chC and chD inparallel at the same time.

Similarly, B components of the second field are divided into two groupsthat are respectively read out on two scan outputs chA and chB inparallel at the same time. Gb components of the second field are dividedinto two groups that are respectively read out on two scan outputs chCand chD in parallel at the same time.

Scan patterns for the scan outputs chA to chD are determined inaccordance with the following rules.

-   chA: Pixel signals are output in an order from a lower pixel in a    screen to an upper pixel (in main scan). This main scan is repeated    from left to right in the screen (in sub-scan).-   chB: Pixel signals are output in an order from an upper pixel in the    screen to a lower pixel (in main scan). This main scan is repeated    from left to right in the screen (in sub-scan).-   chC: Pixel signals are output in an order from an upper pixel in the    screen to a lower pixel (in main scan). This main scan is repeated    from right to left in the screen (in sub-scan).-   chD: Pixel signals are output in an order from a lower pixel in the    screen to an upper pixel (in main scan). This main scan is repeated    from right to left in the screen (in sub-scan).

[Process for Generating Pixel Signal Packs]

Next, a process for generating pixel signal packs is described. Thisprocess is a feature of the second embodiment.

FIG. 8 shows the process for generating pixel signal packs for the Rcomponent.

As shown in FIG. 8, generation of the pixel signal packs of the Rcomponents uses line buffers 18 corresponding to four read-out lines.

The scan control unit 17 writes the pixel signals of the R component(chA and chB) in the line buffers 18 for two lines.

Then, the scan control unit 17 reads out pixel signals of pixels locatedat symmetric positions with respect to a midpoint of the read-out line(i.e., a midpoint between the c-th pixel and the (c+1)th pixel) from theline buffers 18 for two lines and groups the thus read pixel signals.The groups of the pixel signals are sequentially output as pixel signalpacks.

The scan control unit 17 writes the next pixel signals of the Rcomponents (chA and chB) into the line buffers 18 for the remaining twolines in parallel with the above reading operation of the pixel signalpacks.

By exchanging roles of the line buffers 18 so as to alternately read andwrite, it is possible to process the pixel signals of the R component(chA and chB) output from the imaging device 13 without delay.

FIG. 9 shows the process for generating pixel signal packs for the Grcomponent. The process for the Gr component is performed in a similarmanner to that for the R component described above. Therefore, thedescription of the process for the Gr component is omitted here.

[Conversion Process of a Scan Pattern]

FIG. 10 shows a process for converting a scan pattern. The scan controlunit 17 scans and writes the pixel signal packs of the R component andthe pixel signal packs of the Gr component that are generated in theabove manner into the memory 19. Then, the scan control unit 17 scansand reads out the pixel signal packs from the memory 19 in a differentscan pattern from the pattern of the write scan. The scan pattern isconverted according to a difference between scan paths for write scanand for read scan.

The scan control unit 17 rearranges the thus read pixel signal packs insuch a manner that the R component and the Gr component are alternatelyarranged, and outputs the rearranged pixel signal packs to the scanimage processing unit 20 provided in the latter part.

Two memories 19 may be used so as to independently perform conversion ofthe scan pattern of the R component and conversion of the scan patternof the Gr component. Moreover, two other memories 19 may be furtheradded so as to exchange their roles and alternately perform scan forwriting of the first field and read scan for the second field.

A series of the processes described above can convert the scan patternsof the scan outputs chA to chD of the imaging device 13, therebyconverting the first field into a scan pattern shown in FIG. 11A.

FIG. 11B shows a pattern obtained by converting the scan pattern of thesecond field. The process for the second field is the same as that forthe first field described above. Therefore, the description of theprocess for the second field is omitted here.

Although FIGS. 11A and 11B show an example of converting a scan patterninto a pattern of closing-in scan, the second embodiment is not limitedthereto. In the second embodiment, it is possible to perform conversionof a scan pattern into various patterns, e.g., a pattern of split-openscan and a pattern of N-blade scan, by performing the methods describedin the first embodiment.

Effects of the Second Embodiment and Others

As described above, the same effects as those obtained in the firstembodiment can be also obtained in the second embodiment.

Especially, in the second embodiment, it is possible to orderly processthe scan outputs chA to chD of the imaging device 13 that containinformation on a plurality of colors, thereby converting a complicatedscan pattern that is intrinsic to an imaging device into a plain scanpattern suitable for signal processing. Therefore, by providing the scanconversion device 16 of the second embodiment in the electronic camera11, processing of pixel signals after conversion can be made simple andplain.

Supplement of the Embodiments

In the above embodiments, a case is described in which two pixel signalsare grouped into a single pixel signal pack. However, the presentinvention is not limited thereto. For example, three or more pixelsignals may be grouped into a single pixel signal pack. Grouping threeor more pixel signals can realize more scan patterns. For example, it ispossible to divide a screen into N regions and perform N-blade scan forthe N divided regions while performing closing-in scan or split-openscan in each region.

Moreover, in the above embodiments, the main scanning direction of theimaging device 13 is the vertical direction in the screen and the secondmain scanning direction after conversion of a scan pattern is thehorizontal direction in the screen. However, the present invention isnot limited thereto. The main scanning direction of the imaging device13 may be the horizontal direction in the screen and the second mainscanning direction after conversion of a scan pattern may be thevertical direction in the screen. Moreover, it is possible to flexiblytreat conversion of a scan pattern of pixels in a honeycomb arrangementby appropriately setting the main scanning direction and the second mainscanning direction, for example.

Furthermore, a scan pattern of an image taken by the imaging device 13is converted in the above embodiments. However, the present invention isnot limited thereto. For example, a scan pattern may be converted for apartial image (e.g., a cropped image) of the image taken by the imagingdevice 13. Moreover, a scan pattern of an input image (e.g., an imageobtained by scanning a film) may be converted by mounting the scanconversion device 16 of the present invention onto a scanner.

In the aforementioned embodiments, the pixel signal packs may betransferred by parallel transfer or serial transfer in the scanconversion device 16.

Principles of the Embodiments

In order to easily apply the present invention to other embodiments,principles of the above embodiments is now described.

(1) In the embodiment, an input image is temporarily stored on aread-out line basis. The read-out lines extend in the main scanningdirection. N pixel signals are sequentially selected from the read-outline in accordance with a predetermined pixel combination rule. Pixelsignal packs each containing N pixel signals are sequentially output.

This process can reduce the number of the pixel signal packs to beprocessed to n/N where the number of pixels in each read-out line is n.Thus, when a sufficient transfer bandwidth for the pixel signal pack(corresponding to N pixel signals) is ensured, margin of an internalsequence in the scan conversion device is increased by the amountcorresponding to reduction in the number of transfers.

Then, in the embodiment, these pixel signal packs are temporarily storedand are aligned in a direction different from the main scanningdirection (i.e., the second main scanning direction). The pixel signalpacks aligned in the second main scanning direction are scanned andoutput in a predetermined order.

This process converts the main scanning direction intrinsic to the inputimage into the second main scanning direction. Moreover, since the pixelsignal packs each containing N pixel signals are output in this process,a scan pattern can be achieved in which N output lines in the secondmain scanning direction are output in parallel. By employing the scanpattern that enables the use of a plurality of lines, it is possible toeasily shorten time required for scan and easily perform signalprocessing later by using a plurality of lines (i.e., perform the signalprocessing in parallel).

(2) The configuration in the above embodiments can provide various typesof scan patterns by appropriately setting a rule for generating thepixel signal packs and an order of outputting the pixel signal packs.

For example, the pixel signal pack is generated by combining pixelsignals that correspond to symmetric pixels with respect to a midpointof a read-out line with each other. The pixel signal packs are thenaligned in the second main scanning direction and are output in such amanner that pixel signal packs formed of pixel signals at both ends areoutput first. Then, pixel signal packs formed of pixel signals inwardlyadjacent to the one at both ends are sequentially output.

By setting a scan output operation in this manner, it is possible toachieve a scan pattern in which scanning lines respectively startingfrom both ends of a screen come close to each other toward the middle ofthe screen (i.e., a pattern of closing-in scan).

(3) Moreover, the pixel signal pack is generated by combining pixelslocated at symmetric positions with respect to the midpoint of theread-out line, for example. The pixel signal packs are then aligned inthe second main scanning direction for output in such a manner that thescan output starts at pixel signal packs at the center and then itcontinues sequentially in outward directions.

By setting the scan output operation in this manner, it is possible toachieve a scan pattern in which the scanning lines starting from themiddle of the screen gets away from each other toward both ends of thescreen (i.e., a pattern of split-open scan).

(4) Another scan pattern can be also obtained.

For example, N pixel signals selected from the read-out line at apredetermined interval are grouped into a pixel signal pack. The pixelsignal packs are then aligned in the second main scanning direction andare sequentially scanned and output.

By setting the scan output operation in this manner, it is possible toachieve a scan pattern in which N scanning lines that are away from eachother at a predetermined interval progress toward one direction together(i.e., a pattern of N-blade scan).

(5) In the embodiment, the pixel signal may be a color signal containinga signal of information on color of a corresponding pixel. In this case,a scan pattern of a color input image can be converted.

(6) An electronic camera of the embodiment includes the aforementionedscan conversion device. This scan conversion device can convert a scanpattern obtained by an imaging unit into a scan pattern suitable forprocessing in the electronic camera.

The invention is not limited to the above embodiments and variousmodifications may be made without departing from the spirit and scope ofthe invention. Any improvement may be made in part or all of thecomponents.

1. A scan conversion device converting a scan pattern of an input image,comprising: a first buffer unit temporarily storing therein a pixelsignal of the input image on each read-out line in a main scanningdirection of the input image; a pixel packing unit selecting every N(N≧2) pixel signals from pixel signals on the read-out line and groupingthem, for output, into pixel signal packs in accordance with apredetermined pixel combination rule; a second buffer unit temporarilystoring therein the pixel signal packs and aligning them in a secondmain scanning direction that is different from the main scanningdirection; and a scan output unit sequentially scanning, for output, thepixel signal packs aligned in the second main scanning direction in saidsecond buffer unit, wherein a scan pattern of the input image is changedinto a scan pattern in which every N output lines in the second mainscanning direction are output, wherein said pixel packing unit selectsevery N pixel signals from pixels on the read-out line at apredetermined interval and groups them into pixel signal packs foroutput; said scan output unit sub-scans scan outputs of the pixel signalpacks in one direction of the read-out line, the pixel signal packsbeing aligned in the second main scanning direction; and through theoperations of said pixel packing unit and said scan output unit, thescan conversion device achieves a scan pattern in which N dividedregions in a screen are scanned for output in parallel (N-blade scanwhich moves similarly to a N-blade razor skimming the screen).
 2. Thescan conversion device according to claim 1, wherein: the pixel signalsare color signals each containing color information.
 3. An electroniccamera comprising: a scan conversion device according to claim 1; and animaging unit photoelectrically converting an image of a subject andreading out pixel signals, wherein said scan conversion device convertsa scan pattern of the pixel signals read out from said imaging unit.